I was thinking of sourcing a larger cylinder head and throwing it on the stock engine while I mull over whether I really want to bore and stroke. But, if the larger headspace causes poorer performance with the stock cylinder/crank then obviously that wouldn't make sense. Hopefully someone will chime in and clear that up.
Anyway, I started pulling the trash engine apart. I am really confused by these studs. One only has 2 threads engagement, max. The other has excess? What happened here?
It looks like the guy stored this cylinder head cover under a tree.
One side of cylinder looks OK, other side has soot all over it. Definitely doesn't look honed unless the guy has no idea how to cross-hatch.
Piston scrubbing
Interestingly the piston is textbook for "damage from debris getting through air filter". This site that explains diagnosing type of piston failure is for 2-stroked but still an interesting read -
http://www.madsens1.com/saw_piston_fail.htm